A method may include removing a portion of a base component adjacent to a damaged portion of the base component to define a repair portion of the base component. The base component may include a cobalt- or nickel-based superalloy, and the repair portion of the base component may include a through-hole extending from a first surface of the base component to a second surface of the base component. The method also may include forming a braze sintered preform to substantially reproduce a shape of the through-hole. The braze sintered preform may include a Ni- or Co-based alloy. The method additionally may include placing the braze sintered preform in the through-hole and heating at least the braze sintered preform to cause the braze sintered preform to join to the repair portion of the base component and change a microstructure of the braze sintered preform to a brazed and diffused microstructure.

A method for repairing a tip portion of a turbine component having a structural defect is provided. The method includes removing a damaged section in turbine component with a structural defect in a tip portion of the turbine component. A pre-sintered preform is provided including a first portion having a first composition and a second portion having a second composition. The pre-sintered preform is configured to mate with an upper surface of a remaining portion of the turbine component. The method also includes applying the pre-sintered preform to the upper surface, wherein the PSP comprises a superalloy material and a braze material. The PSP and the remaining portion of the turbine component are subjected to a brazing process to melt the braze material and fill in the structural defect.

An airfoil for a gas turbine engine includes a first portion joined to a second portion along an interface such that at least the first portion establishes an airfoil section and the second portion establishes a root section. The airfoil section includes an airfoil body that extends between leading and trailing edges in a chordwise direction, between pressure and suction sides separated in a thickness direction, and from the root section to a tip portion in a spanwise direction. A recessed region extends inwardly from at least one of the pressure and suction sides. The airfoil body includes at least one rib that bounds a respective pocket within a perimeter of the recessed region. The recessed region and the at least one rib are dimensioned to extend across the interface. A cover skin is coupled to the airfoil body along the at least one rib to enclose the recessed region.

A nickel-based braze alloy composition includes nickel, about 1 weight % to about 5 weight % boron (B); and about 1 weight % to about 20 weight % germanium (Ge). The composition is free of any silicon. Superalloy articles having a crack or other type of void or gap may be filled with the nickel-based braze alloy composition. Methods for filling such a gap are described.

Combining a precipitation-hardening nickel-base alloy with a steel or titanium substrate makes it very easy to repair parts, the nickel-base alloy having good erosion-resistant properties. A method for producing is disclosed. In particular for repairing, a component having a substrate, in particular turbine blades made of steel or titanium, in particular made of martensitic or precipitation-hardening chromium-rich steels, with a localized deposition weld or with an affixed shaped part, in which a precipitation-hardening nickel-based alloy is used as the localized deposition weld or as the shaped part, in which a laser powder deposition weld or an arc deposition weld is performed.

An airfoil includes a first airfoil piece and a second airfoil piece that is bonded to the first airfoil piece at a joint. The first airfoil piece and the second airfoil piece are formed of aluminum alloys. At least one of the aluminum alloys is an aluminum alloy composition that has greater than 0.8% by weight of zinc. The joint includes a braze element of magnesium, zinc, or combinations thereof in a higher concentration than in other portions of the first airfoil piece and the second airfoil piece.

A system may include a current source; a first metal or alloy component with a first major surface electrically coupled to the current source; a second metal or alloy component with a second major surface electrically coupled in series to the first component and the current source via an external electrical conductor, where the first and second major surfaces are positioned adjacent to each other to define a joint region; a metal or alloy powder disposed in at least a portion of the joint region; and a controller. The controller may be configured to cause the current source to output an alternating current that conducts through the first component and the second component to induce magnetic eddy currents, magnetic hysteresis, or both within at least a portion of the metal or alloy powder disposed in at least the first portion of the joint region.

An assembly for a dual-walled component of a gas turbine engine and methods of forming and repairing a dual-walled component. The assembly includes a cold section part having an outer surface that defines a plurality of impingement apertures, a hot section part including a pre-sintered preform, the hot section part positioned over the outer surface of the cold section part, and a plurality of support structures including the pre-sintered preform, the plurality of support structures positioned between the hot section part and the cold section part, the plurality of support structures separating the hot section part from the cold section part to define at least one cooling channel therebetween.

An airfoil for a gas turbine engine includes a first portion joined to a second portion along an interface such that at least the first portion establishes an airfoil section and the second portion establishes a root section. The airfoil section includes an airfoil body that extends between leading and trailing edges in a chordwise direction, between pressure and suction sides separated in a thickness direction, and from the root section to a tip portion in a spanwise direction. A recessed region extends inwardly from at least one of the pressure and suction sides. The airfoil body includes at least one rib that bounds a respective pocket within a perimeter of the recessed region. The recessed region and the at least one rib are dimensioned to extend across the interface. A cover skin is coupled to the airfoil body along the at least one rib to enclose the recessed region.

A method of furnace-less brazing of a substrate is provided. The method includes providing a substrate having a brazing region thereon; disposing braze precursor material containing a nickel powder, an aluminum powder, and a platinum group metal powder on the brazing region; and initiating an exothermic reaction of the braze precursor material such that the exothermic reaction produces a braze material that reaches a braze temperature above the liquidus temperature for the braze material. A braze precursor material is also provided.